fixing the year issue in TestStepAggregate

[szamuboy]

The following changes are implemented

The TestStepAggregate function in exec_aggregate_test.go contained the current year hardcoded. Now, it's dynamic.

Changes in the user interface:

N/A

Checklist when submitting a final (!draft) PR

• Commits are tidied up, squashed if needed and follow guidelines in CONTRIBUTING.md
• Code builds
• All existing tests pass
• All new critical code is covered by tests
• PR is linked to the relevant issue(s)
• Rebased with the target branch

[Fajfa]

Thanks, merged